Guralp Systems Limited
MAN-D16-0001

Chapter 1. Introduction

The DM16-R8 is a 16 bit, 8 input-channel digitizer, configured in a standard 1U 19inch rack unit. The primary purpose of the instrument is for use in a seismic data collection station with multiple telemetric input channels.

The eight individual differential input channels are accessed via isolated BNC plugs on the front panel, labelled from A to H. Alternatively, all eight inputs are provided at the rear of the 19inch unit via a single 25pin ‘D’ plug (see pin-outs in appendices).

Other features include

The input stages of all the differential amplifiers are protected against excessive input voltages and limited to ±10V.. Each input is furnished with an inductor and capacitor network to filter out the high frequency signals and enable a minimum of 100dB of common mode rejection.

To minimise ground loops the differential power supply is isolated. Two sets of dedicated dc-dc converters ensure low noise dc supply voltages to the input stages and the digitizer electronics.

1.1 Options

Güralp Systems also manufacture a 16-channel DM16 unit, the DM16R16. This is a 2U rack-mount module containing two 8-channel digitizers with cascaded output. A single GPS unit can synchronize both digitizers to the same time base.

The DM16R16 can optionally be supplied with an internal CMG-DCM data communications module. The DCM is a low-power network device running a full Linux operating system, providing a cost-effective way to connect multiple analogue data sources to a modern TCP/IP network. The DM16R16DCM also fits within a 2U rack space.